I do almost nothing on LinkedIn. I used to keep it up to date; I still have hundreds of outdated, barely relevant contacts. My CV hasn't been updated in years.
And yet recruiters keep finding me through LinkedIn, and I keep getting freelance positions through those recruiters. I put very little effort in finding new positions, but they're always available.
A coworker on my current project who is also a freelancer is much more active. He tries to contact people in companies he wants to work for and gets interesting jobs that way without having recruiters as middlemen. That takes more effort but saves money. Maybe I should do that too.
Maybe it's different for freelancers. Maybe the Dutch market is different from the author's market. I'm no fan of LinkedIn, but it seems to work for me.